The Control Talk Blog provides guidance from a user's viewpoint on the design of automation systems, equipment, and piping for process control improvement. Details are offered on the selection and installation of PID controllers, control valves, variable speed drives, and measurements to maximize loop performance. The blogs are often more intensive and extensive and less vendor specific than a white paper. The goal is an advancement of the profession by sharing conceptual principle based knowledge.

Greg McMillan is a retired Senior Fellow from Solutia/Monsanto and an ISA Fellow. At present, McMillan is a part time modeling and control consultant in Technology for Process Simulation for Emerson Automation Solutions specializing in the use of the Virtual Plant for exploring new opportunities. He spends most of his time writing, teaching and leading the ISA Mentor Program he founded in 2011. He received the ISA Kermit Fischer Environmental Award for pH control in 1991, received the Control magazine Engineer of the Year Award for the Process Industry in 1994, was inducted into the Control magazine Process Automation Hall of Fame in 2001, was honored by InTech magazine in 2003 as one of the most influential innovators in automation, and received the ISA Life Achievement Award in 2010.

Checklist for Best Inline Flowmeter Performance

Nearly all process inputs are flows. The measurement of flow is important for process analysis, metrics, and modeling, reducing variability of process inputs, enabling feedforward and ratio control, and isolating valve nonlinearities by secondary flow loops. Inline flow meters offer the best accuracy and rangeability. Here is a list to help select and install an inline flow meter.

The straight run requirement for inline meters has not been detailed to the extent of orifice meters, flow tubes, and venturi differential head flow meters. The supplier is typically the source of most of the expertise. In an attempt to provide some guidance for the user I have roughly correlated straight run requirements for vortex, turbine, and magnetic flow meters to the ASME guideline for flow tubes. More details need to be consolidated that quantify piping system requirements and effects on inline meter accuracy, noise, and rangeability.

The following checklist is not intended to cover all the specification requirements but some of the major application details to be addressed for inline meters (Coriolis, magnetic, turbine, and vortex meters). The following list assumes the materials of construction have been properly specified, the meter will work safely and reliably with acceptable accuracy for the maximum possible temperature, and electrical connections and enclosure meet electrical area classification and codes in plant. For more information on flow measurement see the March 2012 Control Talk column "Going with the Flow." For a detailed understanding see Chapter 4 in the ISA book Essentials of Modern Measurements and Final Elements in the Process Industries. Reliability, precision (noise, repeatability, resolution, and threshold sensitivity), and turndown (rangeability) are most important.

Join the discussion

Comments

Submitted by Jack Dani on Thu, 07/12/2012 - 09:38

<p>
"I need a motor with the following specs for my project</p>
<p>
Enclosure: TEFC</p>
<p>
Phase: 3 </p>
<p>
Hz: 60 </p>
<p>
Frame: 56C</p>
<p><br /></p>
<p>Now I found one on here that is compatible</p>
<p><a href="https://www.mrosupply.com/product/26523-Baldor_Electric_Motors-Motors_AC_Motors_General_Purpose">https://www.mrosupply.com/product/26523-Baldor_Electric_Motors-Motors_AC_Motors_General_Purpose</a></p>
<p>
But I am unsure of the brand, has anyone ever used a motor of the Baldor brand, and is there a site that will ship to Europe? (this one wont)</p>

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